Azara [10] has described
a gregarious spider in Paraguay, which Walckanaer thinks
must be a Theridion, but probably it is an Epeira, and
perhaps even the same species with mine. I cannot, however,
recollect seeing a central nest as large as a hat, in which,
during autumn, when the spiders die, Azara says the eggs are
deposited. As all the spiders which I saw were of the same
size, they must have been nearly of the same age. This
gregarious habit, in so typical a genus as Epeira, among
insects, which are so bloodthirsty and solitary that even
the two sexes attack each other, is a very singular fact.
In a lofty valley of the Cordillera, near Mendoza, I found
another spider with a singularly-formed web. Strong lines
radiated in a vertical plane from a common centre, where the
insect had its station; but only two of the rays were connected
by a symmetrical mesh-work; so that the net, instead of being,
as is generally the case, circular, consisted of a wedge-shaped
segment. All the webs were similarly constructed.
[1] Venda, the Portuguese name for an inn.
[2] Annales des Sciences Naturelles for 1833.
[3] I have described and named these species in the Annals of
Nat. Hist., vol. xiv. p. 241.
[4] I am greatly indebted to Mr. Waterhouse for his kindness
in naming for me this and many other insects, and giving me
much valuable assistance.
[5] Kirby's Entomology, vol. ii. p. 317.
[6] Mr. Doubleday has lately described (before the Entomological
Society, March 3rd, 1845) a peculiar structure in the wings
of this butterfly, which seems to be the means of its making
its noise. He says, "It is remarkable for having a sort of
drum at the base of the fore wings, between the costal nervure
and the subcostal. These two nervures, moreover, have a peculiar
screw-like diaphragm or vessel in the interior." I find in
Langsdorff's travels (in the years 1803-7, p. 74) it is said,
that in the island of St. Catherine's on the coast of Brazil,
a butterfly called Februa Hoffmanseggi, makes a noise, when
flying away, like a rattle.
[7] I may mention, as a common instance of one day's (June 23rd)
collecting, when I was not attending particularly to the
Coleoptera, that I caught sixty-eight species of that order.
Among these, there were only two of the Carabidae, four
Brachelytra, fifteen Rhyncophora, and fourteen of the
Chrysomelidae. Thirty-seven species of Arachnidae, which I
brought home, will be sufficient to prove that I was not
paying overmuch attention to the generally favoured order
of Coleoptera.
[8] In a MS. in the British Museum by Mr. Abbott, who made
his observations in Georgia; see Mr. A. White's paper in the
"Annals of Nat. Hist.," vol. vii. p. 472. Lieut. Hutton has
described a sphex with similar habits in India, in the "Journal
of the Asiatic Society," vol. i. p. 555.
[9] Don Felix Azara (vol. i. p. 175), mentioning a hymenopterous
insect, probably of the same genus, says he saw it dragging
a dead spider through tall grass, in a straight line to its
nest, which was one hundred and sixty-three paces distant. He
adds that the wasp, in order to find the road, every now and
then made "demi-tours d'environ trois palmes."
[10] Azara's Voyage, vol. i. p. 213
CHAPTER III
MALDONADO
Monte Video - Excursion to R. Polanco - Lazo and Bolas -
Partridges - Absence of Trees - Deer - Capybara, or River
Hog - Tucutuco - Molothrus, cuckoo-like habits - Tyrant-
flycatcher - Mocking-bird - Carrion Hawks - Tubes formed
by Lightning - House struck.
July 5th, 1832 - In the morning we got under way, and stood
out of the splendid harbour of Rio de Janeiro. In our passage
to the Plata, we saw nothing particular, excepting on one day
a great shoal of porpoises, many hundreds in number. The whole
sea was in places furrowed by them; and a most extraordinary
spectacle was presented, as hundreds, proceeding together by
jumps, in which their whole bodies were exposed, thus cut the
water. When the ship was running nine knots an hour, these
animals could cross and recross the bows with the greatest of
ease, and then dash away right ahead. As soon as we entered
the estuary of the Plata, the weather was very unsettled. One
dark night we were surrounded by numerous seals and penguins,
which made such strange noises, that the officer on watch
reported he could hear the cattle bellowing on shore. On a
second night we witnessed a splendid scene of natural fireworks;
the mast-head and yard-arm-ends shone with St. Elmo's light;
and the form of the vane could almost be traced, as if it had
been rubbed with phosphorus. The sea was so highly luminous,
that the tracks of the penguins were marked by a fiery wake,
and the darkness of the sky was momentarily illuminated by
the most vivid lightning.
When within the mouth of the river, I was interested by
observing how slowly the waters of the sea and river mixed.
The latter, muddy and discoloured, from its less specific
gravity, floated on the surface of the salt water. This was
curiously exhibited in the wake of the vessel, where a line
of blue water was seen mingling in little eddies, with the
adjoining fluid.
July 26th. - We anchored at Monte Video. The Beagle
was employed in surveying the extreme southern and eastern
coasts of America, south of the Plata, during the two succeeding
years. To prevent useless repetitions, I will extract
those parts of my journal which refer to the same districts
without always attending to the order in which we visited
them.
